This invention relates to surgical manipulators and more particularly to robotic assisted apparatus for use in surgery.
In standard laparoscopic surgery, a patient""s abdomen is insufflated with gas, and trocar sleeves are passed through small (approximately xc2xd inch) incisions to provide entry ports for laparoscopic surgical instruments. The laparoscopic surgical instruments generally include a laparoscope for viewing the surgical field, and working tools such as clamps, graspers, scissors, staplers, and needle holders. The working tools are similar to those used in conventional (open) surgery, except that the working end of each tool is separated from its handle by an approximately 12-inch long extension tube. To perform surgical procedures, the surgeon passes instruments through the trocar sleeves and manipulates them inside the abdomen by sliding them in and out through the sleeves, rotating them in the sleeves, levering (e.g., pivoting) the sleeves in the abdominal wall, and actuating end effectors on the distal end of the instruments.
In robotically-assisted and telerobotic surgery (both open surgery and endoscopic procedures), the position of the surgical instruments is controlled by servo motors rather than directly by hand or with fixed clamps. The servo motors follow the motions of a surgeon""s hands as he/she manipulates input control devices at a location that may be remote from the patient. Position, force, and tactile feedback sensors may be employed to transmit position, force, and tactile sensations from the surgical instrument back to the surgeon""s hands as he/she operates the telerobotic system.
The servo motors are typically part of an electromechanical device that supports and controls the surgical instruments that have been introduced directly into an open surgical site or through trocar sleeves into the patient""s abdomen becomes a body cavity. During the operation, the electromechanical device or instrument holder provides mechanical actuation and control of a variety of surgical instruments, such as tissue graspers, needle drivers, etc, that each perform various functions for the surgeon, i.e., holding or driving a needle, grasping a blood vessel or dissecting tissue.
This new method of performing telesurgery through remote manipulation will create many new challenges. One such challenge is that different surgical instruments will be attached and detached from the same instrument holder a number of times during an operation. In laparoscopic procedures, for example, the number of entry ports into the patient""s abdomen is generally limited during the operation because of space constraints as well as a desire to avoid unnecessary incisions in the patient. Thus, a number of different surgical instruments will typically be introduced through the same trocar sleeve during the operation. Likewise, in open surgery, there is typically not enough room around the surgical site to position more than one or two surgical manipulators, and so the surgeon""s assistant will be compelled to frequently remove instruments from the holder and exchange them with other surgical tools.
What is needed, therefore, is an improved system and method for releasably coupling a surgical instrument to an instrument holder. The system should be configured to quickly and easily engage and disengage the instrument from the holder to minimize the instrument exchange time during endoscopic surgery. Preferably, the system is part of an electromechanical device that can be coupled to a controller mechanism to form a telerobotic system for operating the surgical instrument by remote control.
According to the invention, a system and method provide for releasably holding a surgical instrument during conventional open surgery or endoscopic procedures, such as laparoscopy. The instrument comprises an elongate shaft with proximal and distal ends and a mounting means having a protrusion extending radially from the shaft between the proximal and distal ends. An instrument holder comprises a support having a body with an axial passage for receiving the instrument shaft and a first hole in communication with the axial passage for receiving the protrusion. A second hole is cut into the body transversely to and in communication with the first hole so that the protrusion can be rotated within the second hole. To prevent the instrument from being accidently twisted and thereby disengaged from the instrument holder during surgery, the holder further includes a locking means coupled to the body for automatically locking the protrusion within the second hole thereby releasably locking the instrument to the instrument holder.
In a preferred configuration, the protrusion of the mounting means comprises a pair of opposing arms, such as mounting pins, extending outward from the instrument shaft. The first hole is an axially extending slot for receiving the mounting pins and the second hole is a perpendicular locking slot having a first portion aligned with the axial slot and a second portion extending circumferentially around the body of the instrument support. With this configuration, the mounting pins can be slid through the axial slot and rotated into the locking slot to attach the instrument to the holder. The instrument can be removed by performing the same two steps in reverse order. With this twist-lock motion, the surgeon can rapidly engage and disengage various instruments from the instrument holder during a surgical procedure.
The locking means preferably comprises a releasable latch assembly for locking the mounting pins to the instrument holder. The latch assembly includes a spring-loaded plunger coupled to a latch that normally locks the instrument in place by capturing the mounting pin in the locking slot. The plunger has a button extending outward from the instrument holder for moving the latch away from the locking slot. The button can be depressed manually or automatically to release the mounting pins and allow instrument exchange when the instrument is easily accessible to the surgeon.
The invention is particularly useful for releasably holding an endoscopic instrument configured for introduction through a small percutaneous penetration into a body cavity, e.g., the abdominal or thoracic cavity. To that end, the instrument preferably includes an end effector, such as a pair of jaws, coupled to the distal end for engaging a tissue structure within the body cavity. To actuate the end effector, the instrument has a second pair of arms, such as actuator pins, laterally extending from the shaft and operatively coupled to the end effector. Preferably, the actuator pins are axially displaceable with respect to the shaft to actuate the end effector (e.g., open and close the jaws). The instrument holder further includes an actuator driver releasably coupled to the actuator arms and to an external driver for actuating the end effector. The actuator driver preferably includes a twist-lock interface having transverse slots similar to that described for the instrument support so that the instrument can be simultaneously engaged or disengaged from both the instrument support and the actuator driver.
Other features and advantages of the invention will appear from the following description in which the preferred embodiment has been set forth in detail in conjunction with the accompanying drawings.